# TS2515: Non-abstract class '…' does not implement inherited abstract member … from class '…'.

> A concrete class extends an abstract class but doesn't implement one of its abstract members. Implement the member, or make the class abstract too.

## What it means

Every abstract member of a base class must be implemented by the first non-abstract class that
extends it. The class name is reported with the missing member and the class that declares it.

## Example

```ts
abstract class Shape {
  abstract area(): number;
}
export class Circle extends Shape {}
```

## How to fix

- Implement the member in the class (here an `area()` method).
- Or mark the class `abstract` and implement it in a further subclass.

Source: https://ts-r.dev/errors/TS2515/